Apparatus for applying filamentary material to a workpiece

ABSTRACT

An output roller has filamentary material pulled off from it under tension so that the material can be applied to the workpiece. One or more supply spools carry a supply of the filamentary material and are rotatable in response to the withdrawal of such material as it is being furnished to the output roller. A braking arrangement is displaceable between a first and a second operative mode in which it respectively permits and prevents the rotation of the supply spools and consequently the withdrawal of the filamentary material from them. A loop-forming arrangement permanently tends to move from an inoperative position to an operative position in which latter it form a storage loop from a length of the filamentary material intermediate the output roller and the supply spools. The loopforming arrangement responds by moving to its operative position when the braking arrangement moves to its first operative mode in which it permits rotation of the supply spools. When a loop is formed, the braking arrangement is automatically made to move back into its second mode, so that the output roller can now withdraw filamentary material only from the loop until the length of material making up the loop is used up whereupon the loopforming arrangement returns to its inoperative position. A release arrangement displaces the braking arrangement to the first mode of operation in automatic response to the movement of the loop-forming arrangement toward the inoperative position thereof.

United States Patent Ostermann 1 Mar. 25, 1975 1 1 APPARATUS FORAPPLYING FILAMENTARY MATERIAL TO A WORKPIECE [57] ABSTRACT An outputroller has filamentary material pulled off from it under tension so thatthe material can be applied to the workpiece. One or more supply spoolscarry a supply of the filamentary material and are rotatable in responseto the withdrawal of such material as it is being furnished to theoutput roller. A braking arrangement is displaceable between a first anda second operative mode in which it respectively permits and preventsthe rotation of the supply spools and consequently the withdrawal of thefilamentary material from them. A loop-forming arrangement permanentlytends to move from an inoperative position to an operative position inwhich latter it form a storage loop from a length of the filamentarymaterial intermediate the output roller and the supply spools. Theloop-forming arrangement responds by moving to its operative positionwhen the braking arrangement moves to its first operative mode in whichit permits rotation of the supply spools. When a loop is formed, thebraking arrangement is automatically made to move back into its secondmode, so that the output roller can now withdraw filamentary materialonly from the loop until the length of material making up the loop isused up whereupon the loop-forming arrangement returns to itsinoperative position. A release arrangement displaces the brakingarrangement to the first mode of operation in automatic response to themovement of the loop-forming arrangement toward the inoperative positionthereof.

[75] Inventor: Max Ostermann,

Wuppertal-Barmen, Germany [73] Assignee: W. & M. Ostermann, Wuppertal,

Germany [22] Filed: Feb. 13, 1974 [21] Appl. No.: 442,126

[30] Foreign Application Priority Data Feb. 16, 1973 Germany 2307765[521 U.S. C1. 57/13, 242/147 R [51] Int. Cl B65h 81/08 [58] Field 01Search ..57/3,10,l1,13.14.15,

[56] References Cited UNITED STATES PATENTS 2,619.788 12/1952 Grieve57/13 2.875.570 3/1959 Sarracino t 57/13 2,907,164 10/1959 Grieve et a1.57/13 3.063.228 11/1962 Sarracino 57/3 3.183.583 5/1965 Ostermann...57/13 X 3.233.397 2/1966 Bonikowski 242/45 X 3.344.592 10/1967 Geisinger57/3 3.392.933 7/1968 Singh 242/149 3.486.317 12/1969 Grawey ct a1 5'7/33.553.951 1/1971 Hinds 57/3 3,590.567 7/1971 Bonikowski et al. 57/3Primary E.raminer-John Petrakes Attorney, Agent, or Firm-Michael S.Striker APPARATUS FOR APPLYING FILAMENTARY MATERIAL TO A WORKPIECEBACKGROUND OF THE INVENTION The present invention relates generally toan apparatus for applying filamentary material to a workpiece, and moreparticularly to a winding apparatus for jack eting hoses, conduits,cables or the like with filamen tary material, for instance wires.

Apparatus of this general type is already known and uses a windingsupport that rotates and carries pivot pins which are connected at oneend on the winding support and which carry at their opposite free end abraking disc which can be moved towards and away from the windingsupport and thus into or out of engagement with the spools which arerotatably mounted on the respective pivot pins and from which thefilamentary material is being withdrawn.

This prior-art construction has certain disadvantages, one of which isthe fact that the tension of the filamentary material as the latter isbeing withdrawn depends to a large extent upon the diameter of thefilament package that is present on the particular spool. If the brakedisc is for instance set to impart a certain predetermined brakingeffect to a given spool, it will be appreciated that the filamenttension decreases when filamentary material is continuously withdrawnfrom an initially full spool, that is from a spool which initiallycarries a full filament package. Variations in the filament tension,however, have disadvantageous consequences in terms of the uniformitywith which the filamentary material is applied to the workpiece, forinstance by forming a jacket about the latter. It is conceivable toovercome this problem by constantly readjusting the braking effectafforded by the braking disc, but this is evidently as time consuming asit is cumbersome and labor-intensive; hence, this approach is notpractical in actual use.

SUMMARY OF THE INVENTION Accordingly, it is a general object of thepresent invention to overcome the disadvantages of the prior art. Moreparticularly, it is an object of the present invention to provide animproved apparatus for applying filamentary material to a workpiece,which is not possessed of the aforementioned disadvantages.

Still more particularly, it is an object of the invention to providesuch an improved apparatus wherein a uniform tension of the filamentarymaterial being withdrawn is assured at all times.

Another object of the invention is to provide such an apparatus whereinthe degree of tension that has once been selected, will be variedneither as a result of changes in the package size of a spool from whichthe filamentary material is being withdrawn, nor as a result of otherfactors, such as weights or forces that might otherwise cause such anundue influence, for example at rapid rotation of the winding support.

In keeping with the above objects, and with others which will becomeapparent hereafter, one feature of the invention resides, in anapparatus for applying filamentary material to a workpiece, in acombination which comprises output means from which filamentary materialis pulled off-under tension to be applied to the workpiece. Supply meanscarries a supply of the filamentary material and is rotatable inresponse to withdrawal of the material which is being furnished to theoutput means. Braking means is displaceable between a first and a secondoperative mode in which it respectively permits and prevents rotation ofthe supply means and withdrawal of the filamentary material from thesame. Loop-forming means permanently tends to move from an inoperativeposition to an operative position in which it forms a storage loop froma length of the filamentary material intermediate the output means andthe supply means. The loop-forming means is responsive with movement tothe operative position to a displacement of the braking means into thefirst mode and it causes displacement of the braking means back into thesecond mode as a consequence of the formation of the loop. As a resultof this, the output means can withdraw filamentary material only fromthe loop, not from the supply means directly, and this withdrawalcontinues until the length of filamentary material making up the loop isused up, whereupon the loop-forming means returns to its inoperativeposition. Release means displaces the braking means into its first modeof operation in automatic response to movement of the loop-forming meanstoward the inoperative position.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially sectioned,somewhat diagrammatic side view, illustrating an apparatus embodying theinvention;

FIG. 2 is a fragmentary perspective view, illustrating a detail of theapparatus in FIG. 1;

FIG. 3 is a vertical section through FIG. 2, partly in elevation,illustrating details of that Figure;

FIG. 4 is a diagrammatic side-elevation illustrating one operativeposition of the part of the apparatus that is shown in FIG. 2;

FIG 5 is similar to FIG. 4, illustrating another operative position ofthe apparatus;

FIG. 6 is a fragmentary section, taken on line VI-VI of FIG. 3; and

FIG. 7 is a rear view analogous to FIGS. 4 and 5, that is showing theapparatus as it would appear when looked at from the reverse side ofFIGS. 4 and 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring firstly to FIG. I itwill be seen that this Figure shows in toto and designates withreference numeral 10 an apparatus for applying filamentary material to aworkpiece, here illustrated as a hose or conduit 15 about which a jacketof filamentary material, here in for most steel wires 23, is to beapplied. A portion of the jacketed hose 15 is visible at the left-handside of FIG. I and designated in diagrammatic illustration withreference numeral 25; The direction of advancement of the workpiece,that is the hose I5. is identified by the arrow 16.

The apparatus has a frame or support I2 on which a rotary support orwinding frame 11 is mounted which is turnable in bearings 13. Thewinding frame II is rotatable in a vertical plane and formed with theillus trated central passage extending along its axis of rotation andthrough which the workpiece passes. Filament guiding arrangements 14 areprovided which are well known in the art and require no detaileddiscussion; they serve to guide the filaments onto the workpiece 15.

Of course, it will be understood that a motive means must be provided,for instance a non-illustrated pulloff, which advances the workpiece,that is the hose 15, in the direction of the arrow 16. A gear 17 isfixedly connected with the winding frame 11 which is of essentiallydisc-shaped configuration, so that the winding frame 11 is driven fromits gear 17 which in turn is rotated by engagement with a geartransmission 18 (not shown) located in the gear box 18 and whichreceives its input from the drive shaft 19 which may be driven by amotor. Appropriate couplings may also be provided.

The winding frame 11 is formed at its side facing towards the threadguide arrangements 14 with a plurality of supply units 20 which arearranged on circles that are concentric with the axis of rotation of thewinding frame 11 and which carry spools provided with supplies offilamentary material.

Details of one such unit 20 are most clearly shown in FIG. 2 where itwill be evident that such a unit may comprise one or more (threeillustrated) spools or bobbins 22 that are rotatable about a pin 26which is secured with its end portion 27 to the winding frame 11.Generally speaking, each of the units 20 has a carrier 21 and may haveone, but usually a plurality of the spools 22 each of which carries asupply of the filamentary material 23, which here will be assumed to bein form of steel wires but could of course be a different kind ofmaterial. A thread tensioning arrangement 24 is associated with each ofthe units 20 and the several filaments 23 derived from the variousspools 22 of the respective unit 20 pass jointly through the threadtensioning arrangement 24 before being supplied to the thread guidingdevices 14 shown in FIG. 1, from where they are supplied at the desiredangle of inclination onto the surface of the hose 15 so as to be appliedto the latter as the winding frame 11 rotates about and with referenceto the hose 15, to obtain the jacketed hose diagrammatically illustratedat 25 in FIG. 1.

It will be appreciated that since the hose 15 advances in the directionof the arrow 16, and since the filaments 23 are being wound onto hose15, filaments will be constantly withdrawn from the spools 22 of therespective units 20, so that gradually the amount of filamentarymaterial present on the respective spools 22 becomes exhausted.

Referring now to FIGS. 2 and 3 it will be seen that the longitudinalaxis of the pin 26 extends at right angles to the plane of the windingframe 11. Parenthetically it should be pointed out that if the inventionis embodied in an apparatus for applying filamentary material to a hoseor other workpiece not by winding, but by braiding, the lower endportion 27 of the pin 26 will be guided in a track of the braiding framethat would replace the winding frame 11.

Since the winding frame 11 (or the braiding frame. ifsuch is used)rotates in a vertical plane, the axis of the pins of the several units20 are horizontally oriented, that is they extend in parallelism withthe axis of rotation of the winding frame 11. Between axially adjacentones of the spools 22, and between the lowermost spool 22 and thewinding frame 1 1, there will be friction pads 28 the purpose of whichis to provide sufficient friction to retard completely free rotation ofthe spools 22 with reference to one another and to the winding frame 11.Axially adjacent ones of the spools 22 have the filamentary material 23wound about them in mutually opposite directions. In other words, inFIGS. 2 and 3 for instance the filamentary material 23 is wound aboutthe upper and lowermost spool 22 in clockwise direction whereas it iswound about the intermediate spool in counterclockwise direction. Theadvantage ofthis is that when filamentary material is withdrawn from anyone of the spools 22, the axially adjacent spool or spools cannot betaken along by the rotary movement which the spool performs from whichthe filamentary material is being withdrawn, but are instead slightlybiassed in the opposite rotational direction so as to tension thefilamentary material thereon. This is particu larly important in caseswhere the amount of filamentary material on different spools differs.

The filaments 23 withdrawn from the respective spools 22 ofa unit 20 areguided over rollers 29 located at the level of the respective spool, andare then supplied to a collecting roller 43 of the thread tensioningarrangement 24, from whereon the several (here three) filaments 23continue to travel in unison.

A braking member of disc 30 is located above the upper end of the spools22 in the respective unit 20 and is provided with a friction pad orcovering 33. It is mounted axially movable at the upper free end 31 ofthe pin 26. As indicated by the force vector P in FIG. 3, the brake disc30 is moved in axial direction of the pin 26 to be pressed against theuppermost spool 22 in a manner and by means to be describedsubsequently. The extent of axial movement is very small, and need varyonly within the range of wear of the pad 33 and the compressibilitythereof. Because this distance of axial travel is small, it issufficient to connect the disc 30 with the free end 31 of the pin 26 bymeans of an arrangement which utilizes a circumferential groove 32formed in the end portion 31, and a central hub 34 which surrounds theend portion 31 and is provided with a U- shaped spring 35 the legs ofwhich are pushed through slots formed in the hub 31 so that they engagein the groove 32, as shown in FIG. 2.

A control arm 37 is provided the elongation of which is indicated by thebroken line 38 in FIG. 3 and will be seen to extend parallel to theplane of the winding frame 11. The brake disc 30 is connected rotatablyat 36 with the arm 37, which latter is pivoted at two pivots 39 (note inFIG. 2 that the arm 37 in this embodiment is composed of twotransversely spaced parts which are connected by a connector 41) to asupport 40 which is fixed with reference to the pin 26 and inthe-illustrated embodiment is also carried by the winding frame 11. Thesupport 40 in this embodiment also carries the rollers 29 which havebeen mentioned earlier.

When the filamentary material on the respective spools 22 has beenexhausted. it is necessary to be able to replace them with full ones.For this purpose it is of course necessary that the braking disc 22 bemade removable. This can be done by pivoting the control arm 37 in thedirection of the arrow 83 (see FIG. 4) about the pivot axis 39, thusmoving the control arm 37 which extends radially with respect to thewinding frame 11 upwardly in FIG. 3. The pull exerted thereby causes anautomatic disengagement of the legs of the spring 36 from the pin 26,inasmuch as the legs flex outwardly and snap out of the circumferentialgroove 32. Of course, when the movement is subsequently reversed, theselegs will snap back into the groove. When the control arm 37 has beenthus pivoted upwardly, the spools 22 can readily be withdrawn from thepin 26 for replacement with full ones.

The control arm 37, the dual construction of which is particularlyadvantageous because of the excellent stability and the possibility ofproviding good and solid connections at 36 and '39, is formed at itsfree end (the left end in FIG. 2) with a roller 47 which in theoperative condition of the unit is located in the region of the threadtensioning device 24, as shown in FIG. 2. The filaments which movearound the roller 43 of the thread tensioning device 24, continue to aninput roller 44 which is mounted for rotation in an inclined position.They thus move into that radial plane of the winding frame 11 in whichthe sensing roller 42 on the arm 37 is also located. The filaments 23then pass around the sensing roller 42 and further around a tensioningroller 46 which is turnably mounted on an arm 45 that can be pivoted ina manner still to be described. From the roller 46 the filaments travelvia an output roller 47 to the final output roller 48 from where theyare supplied to the filament guiding arrangements 14.

FIG. 6 shows most clearly that the roller 44 is formed with one or morecircumferential grooves, as are the rollers 46 and 47. These grooves arelocated essentially in a common plane extending radially of the windingframe 11. Because of the manner in which the section of FIG. 6 is taken,the roller 44 would be invisible and it has therefore been shown inbroken lines.

Also shown in FIG. 6 is the fact that the pivot arm 45 carrying thetension roller 46 is connected with a sleeve 49 which is journaled atits opposite axial ends in bearings 50, 51 and thus makes possible thepivoting of the arm 45. The output roller 47 is ring-shaped and isjournaled on the sleeve 49 by means of roller bearings 52. The sleeve 49itself is accommodated in a housing of the device 24, which housing iscomposed of two parts 53 and 54 and is connected to the winding frame 11in the illustrated embodiment. A shaft 55 is accommodated in the housing53, 54 and is surrounded in its middle portion by a torsion spring 56which is accommodated over a substantial portion of its length in thesleeve 49.

A toothed blocking wheel 57 has a hub 59 which is of polygonal interiorcrosssection and into which one end portion of the shaft 55 extendsmatingly so that the two are connected for joint rotation. The wheel 57is located at the exterior of the housing portion 54 and is formed witha sleeve portion 58 which extends into a bore of the housing portion 54.Located on the inner end of the sleeve portion 58 is the bearing 51 forthe sleeve 49, and one end of the torsion spring 56 is fixedly connectedin the region of the shoulder 60 with the shaft 55. The other end of thetorsion spring 56 is connected with a ring 64 which surrounds the shaft55 and is slidable axially of the same. The ring 64 has a radial guidepin 65 which extends into an elongated slot 66 formed in the sleeve 49and extending axially of the latter. That end of the shaft 55 which islocated in the region of the ring 64 is formed with a thread. A nut 61is threaded onto this thread and serves to secure a cover 62 on theshaft 55 so that the cover turns with the shaft. The cover closes a borein the housing portion 53 and is formed with a sleeve portion 63 onwhich the bearing 50 of the sleeve 49 is secured. I

Details of the wheel 57 are visible in the rear view of the arrangementthat is shown in FIG. 7. It will be seen that a double-tooth pawl 67 ispivotably mounted adjacent the wheel 57 on the housing portion 54, bymeans of a screw 68. A spring 69 is connected with the pawl 67 andnormally maintains one tooth of the pawl in engagement with the teeth ofthe wheel 57. It is clear, therefore, that the wheel 57 and the pawl 67together form an escapement. The pawl 67 is provided with a handle 70 bymeans of which an operator can manually pivot the pawl 67 about thepivot axis defined by the screw 68, counter to the force of the spring69, to thereby move one tooth of the pawl 67 out of engagement with theteeth of the wheel 57 to permit the latter to turn in the direction ofthe arrow 71 and under the influence of the torsion spring 56, by thelength of half a tooth in reverse direction. This is possible because atthis time the other tooth of the pawl 67 will already engage again withthe teeth of the wheel 57. When the handle is disengaged, the pawl 67 ofcourse is urged by the spring 69 to the position shown in FIG. 7, inwhich the wheel 57 can turn in the direction opposite to that of thearrow 71 by a distance corresponding to half a tooth, until the firsttoothof the pawl 67 again meshes with the teeth of the wheel 57. Byturning the pawl 67 to and fro by alternately engaging and releasing thehandle 70, it is possible to count exactly by how many teeth the pawl 67permits the wheel 57 to turn while simultaneously permitting arelaxation of the torsion spring 56.

In order to tension the torsion spring 56, flats 72 are formed on thehub 59 of the wheel 57, so that the hub can be engaged with a box wrenchor the like and the shaft can be turned, with the result that thetorsion spring 56 will be tensioned. To do this, the wheel 57 is turnedin the direction opposite to the arrow 71, a movement which is notblocked by the pawl 67 the teeth of which slide over the backs of theteeth on the wheel 57. It is a simple matter for an operator to countthe number of teeth of the wheel 57 which pass by the teeth of the pawl67, since an acoustically detectable ratchet or snap action effect willbe noticeable, and

from the number of teeth thus counted it is possible to determine towhat extent the torsion spring 56 in the housing 53, 54 has beentensioned. It will be understood that while the one end of the torsionspring 56 turns with the shaft 55, the other end which is connected withthe ring 64, can not turn but can shift longitudinally of the shaft 55as the torsion spring is being tensioned and hence contracts axially.This is because the ring 64 can freely slide axially of the shaft 55 butis prevented from rotation due to the interengagement of the components65, 66. In operation of the apparatus, the end portion of the torsionspring which is connected with the shaft 55 can be considered as thefixed end portion, whereas the other end portion connected with the ring64 can be considered as the movable end portion. Once the spring 56 istightened. it tends to displace the shaft 55 and thus the arm 45 in thedirection of the arrow 73 shown in FIG. 3, thus tensioning that lengthof filament which surrounds the roller 46 and is identified withreference numeral 23. being located between the roller 44 and the roller47, and forming it into the shape of a loop. It is the permanenttendency of the roller 46 to move as far as possible in the direction ofthe arrow 73 from the roller 44, by pivoting with the arm 45 about theaxis of rotation defined by the shaft 55. A stop may be provided tolimit this movement in the event that no thread or other filament 23 ispresent which affords such a limitations.

FIGS. 4 and show the arrangement of FIGS. 2 and 3 in somewhatdiagrammatic form. The various rollers have been for the most part shownby broken lines, as if they were transparent, in order to be able tomore clearly show the configuration assumed by the filaments 23.

FIG. 5 shows the arm 45 in a position representing the maximumdisplacement which can occur for the arm 55 under the urging of thetorsion spring. This means that a relatively large loop is formed,composed of the filament length 23'. Depending upon the tension impartedto the torsion spring, the filamentary material which is supplied to thethread guiding devices 14 from the device 24 will have a predetermineddesired tension. Since the filamentary material is guided around theroller 46, the latter will always constitute the apex 74 of the loopformed from the filament portion or length 23. That part of the loopwhich is identified with reference numeral 75 is always straight untilit comes in contact with the roller 47. The other part of the loop isidentified with reference numerals 76, 76 and hence composed of twosections. These two sections 76, 76' will include with one another anangle that may vary between zero as shown in FIG. 8 and FIG. 4 and themaximum angle shown in FIG. 5, depending upon the position of the arm 45and the roller 46. The section 76 will to all intents and purposesalways be located on the line 78 that has been shown for the purposes ofexplanation in FIGS. 4 and 5, whereas the section 76' will be angled toa greater or lesser degree as explained above. The angle a which isincluded between the section 76, 76' will be the more pronounced, thefarther the roller 46 on the arm 45 pivots away from the roller 44 (inclockwise direction in FIGS. 4 and 5). Conversely, the angle a willdecrease as the arm 45 with the roller 46 moves in the oppositedirection from the position of FIG. 5 back to or towards the position ofFIG. 4, counter to the urging of the torsion spring 56.

The principle of operation of this arrangement is based on the fact thatwhen the loop is formed as shown in FIG. 5, the filamentary material 23that is being withdrawn from the device 24 will be directly withdrawnnot from the spools 22, but from the loop formed of the sections 75, 76and 76, until this loop disappears and the sections 76, 76 are locatedon the line 78 shown in FIG. 4 in which the previously formed storageloop has disappeared.

Such a movement of the arm 45 and roller 46 back to the position of FIG.4, and the consequent disappearance of the storage loop, causes avariation in the forces acting upon the sensing roller 42, and aconsequent variation of the forces acting upon the control arm 37. Thiswill be explained with reference to FIGS. 4 and 5.

The filament tension which acts via the roller 46 upon the filamentlength 23' which has been stored in form of the storage loop as shown inFIG. 5, which filament tension is produced by the action of the torsionspring 56 via the arm 45, causes the development of force vectors P,-which are shown in FIG. 5 and which act in the region of the sections76, 76' upon the sensing roller 42. These vectors add up to a resultingforce R which acts along the line 84 upon the control arm 37.

The force acting upon the control arm 37 can be subdivided into twocomponents, namely one component P which acts longitudinally of thecontrol arm 37 in the direction of the line 38 and is absorbed at thepivot axis 39 and thus does not influence the movements of the controlarm 37. The second force component P produces upon the control arm 37 aturning movement which urges the control arm 37 in a direction in whichit presses the brake disc 30 against the spools 22 with a force P whichhas been multiplied by the lever action of the arm 37. The force P is solarge with reference to the existing filament tension, that the filamenttension is not sufficient to cause the spools 22 to rotate, so that thelatter are precluded from such rotation and from paying-out offilamentary material.

This means that as the spools 22 are prevented from rotation,filamentary material that is withdrawn to be applied to the hose 15 canbe withdrawn only from the loop formed of the length 23, thus decreasingthe size of the loop. This causes the roller 46 and the arm 45 to bepivoted counterclockwise in FIG. 5 against the action of the torsionspring until finally the position of FIG. 4 is reached. The resultingforce R mentioned ear lier of course decreases constantly as this takesplace, and thus the force component P acting upon the control arm 37similarly decreases, leading to a corresponding decrease in the brakingforce P all as indicated by the intermediate position shown for the arm45 and the roller 46 in FIG. 3.

Once the position of FIG. 4 has been reached, the roller 44, the roller42 and the roller 46 are located on a common line 78, and the forces Pwhich act in the two sections 76, 76' in the region of the sensingroller 42 are now exactly mutually oriented and when added produce aresulting force R which equals zero. This means that the force componentP acting upon the control arm 37 has also been reduced to zero andsimilarly the braking force P has been reduced to zero, so that thespools 22 are no longer being braked against rotation.

At this time, however, the filaments 23 continue to be subjected to thetension imparted to them via the torsion spring 46, and in fact thistension has slightly increased with respect to the previous position ofFIG. 5, because the torsion spring 56 has been tensioned somewhat moreduring the movement of the arm 45 to the position in FIG. 4. Thisincrease in tension is however minor and to all intents and purposes thepreviously elected level of tension is maintained unchanged. Thisfilament tension, however, is sufficient to cause turning of the spools22 in a sense paying out filamentary material from the latter. The forceacting via the spring 56 and the filamentary material upon the spools 22will be sufficient to cause turning of the latter at the latest when thearm 45 has reached the position of FIG. 4, so that now these spools 22will turn and a length of filamentary material will be unwound from eachof them. Since the filament tension thus becomes relaxed. the torsionspring 56 is able to progressively displace the arm 45 back from theposition of FIG. 4 to the position of FIG. 5, creating a new storageloop such as the one shown in FIG. 5. During this movement the brakingforce P acting upon the braking disc 30 increases again, in accordancewith the relationships that have been outlined earlier, whereby thespools 22 are finally brought to a halt again.

By appropriate selection of the various components, the type of frictionelements used which determine the value of friction between the spoolsand upon the spools, and an appropriate selection of the filamenttension exercised by the spring 56, the length of the filament portion23' forming the loop in FIG. can be determined, and this in turndetermines the extent to which the arm 45 can pivot (in Flg. 5) inclockwise direction. Actually, however, it is not usually possible inpractice to rely entirely upon these considerations, because variousinterferences will occur, based primarily upon a tendency of thematerial of the friction pad 33 of the brake disc 30 to stick to theassociated spool 22. Another source of difficulty is the fact that theoverall diameter of the respective spool 22, that is of the package offilamentary material wound onto the same, varies in dependence upon theamount of filamentary material that has already been withdrawn, thusvarying the torque acting upon the spool when material is beingwithdrawn from the same.

These problems have been overcome by the arrangement according to thepresent invention in that an abutment is provided at the free end of thecontrol arm 37, which serves to aid in lifting of the control arm. Thisabutment can be variously constructed or configurated, but here uses abolt 79 which is eccentrically mounted on the free end of the controlarm 37 by means of a nut and which carries the sensing roller 42. Theeccentricity of the bolt 79 makes possible a variation of the engagementof the bolt 79 with a cooperating abutment 81 which is formed on the armin the manner of a nose as shown in FIG. 3. The bolt 79 extends into thepath of movement of the abutment 81 as the arm 45 pivots, and in theillustrated embodiment the arrangement is so selected that the abutment81 of the arm 45 begins to lift the control arm 37 via the abutment 39thereof when the position shown in FIG. 4 has been reached by the arm45. By differently configurating or positioning (for instance turningthe eccentric bolt 79) the abutments on the arm 37 and the arm 45 it ispossible to obtain an earlier engagement of the two abutments, whichmeans that under all circumstances the arm 37 will reliably lift thebraking disc 40 off the associated spool 22 at the desired time, thuspermitting rotation of the spools 22 in order to free another length offilamentary material. To avoid any possibility of excess tension in thefilamentary material 23 during winding, the abutments constituted by theportions 79 and 81 are so arranged that when the arm 37 is lifted bytheir cooperation, the sensing roller 42 does not cause an undesiredincrease of the angle a included between the two sections 76, 76'.Instead, the abutments serve to assure that the roller 46 will moverapidly once they cooperate with one another, and that thus the angle acannot increase and may even further decrease, which reliably avoidsexcess tension in the filamentary material. In the exemplary embodimentthis means that the arrangement of the rollers 44, 42 and 46 in astraight line will remain unchanged, even as the arm 37 continues tomove upwardly as a result of the cooperation of the components 79 and81. Fi-

nally, when these components contact one another,

they transmit a force which acts tangentially to the arcuate pivotablepath 83 of the component 79, so that the component 81 in effect acts inthe manner of a wedge, sliding underneath the component 79 and liftingthe same.

It will be understood that each of the elements de scribed above, or twoor more together, may also find a useful application in other types ofconstructions differing from the types described above.

While the invention has been illustrated and described as embodied in anapparatus for applying filamentary material to a workpiece, it is notintended to be limited to the details shown, since various modificationsand structural changes may be made without departing in any way from thespirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art fairly constitute essentialcharacteristics of the generic or speciric aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims:

1. In an apparatus for applying filamentary material to a workpiece, acombination comprising output means from which filamentary material ispulled off under tension to be applied to the workpiece; supply meanscarrying a supply of the filamentary material and being rotatable inresponse to withdrawal of such material which is being furnished to saidoutput means; braking means displaceable between a first and a secondoperative mode in which it respectively permits and prevents rotation ofsaid supply means and withdrawalof the filamentary material from thesame; loopforming means permanently tending to move from an inoperativeposition to an operative position in which it forms a storage loop froma length ofsaid filamentary material intermediate said output means andsaid supply means, said loop-forming means being responsive withmovement to said operative position to a displacement of said brakingmeans into said first mode and causing displacement of said brakingmeans back into said second mode as a consequence of the formation ofthe loop, whereby said output means can withdraw filamentary materialonly from said loop until said length of filamentary material is used upand said loopforming means is moved to said inoperative position; andrelease means for displacing said braking means into said first mode inautomatic response to movement of said loop-forming means toward saidinoperative position.

2. A combination as defined in claim 1, wherein said supply meanscomprises a pin and at least one filamentary-material carrying spoolmounted for rotation about said pin and having a free axial end; saidbraking means comprising an arm extending across said free axial endsubstantially normal to said pin and having one end portion mounted forpivotal movement about a pivot axis extending normal to both said pinand the elongation of said arm, and a friction member carried by saidarm and engageable with said free axial end of said spool.

3. A combination as defined in claim 2, said arm having another endportion spaced from said one end portion and carrying a first rollermounted turnably thereon and about which said filamentary material istrained; further comprising a second roller mounted adjacent saidloop-forming means and engaging said filamentary material intermediatesaid supply means and said first roller.

4. A combination as defined in claim 3, said first and second rollerbeing rotatable about substantially parallel first and second axes; andwherein said loop-forming means comprises a third roller rotatable abouta third axes substantially parallel to said first and second axes, and apivot arm having one portion on which said third roller is mounted, andanother portion which is pivoted for displacement about a fourth axisparalleling said third axis, said filamentary material being alsotrained about said third roller downstream of said second roller withreference to the direction of movement of said filamentary materialtowards said output means, so that when said loop is formed by movementof said third roller with said pivot arm in said direction, said loop.includes two filament portions which extend between said first andsecond rollers and between said second and third rollers, respectively,and which include with one another an angle which varies in dependenceupon the extent to which said pivot arm is displaced about said pivotaxis.

5. A combination as defined in claim 4; and further comprising a rotarysupport having an axis of rotation, said means all being mounted on saidsupport for rotation with the same.

6. A combination as defined in claim 5, wherein said arm extendssubstantially parallel to a plane in which angle is open indirectiontowards said rotary support.

1. In an apparatus for applying filamentary material to a workpiece, acombination comprising output means from which filamentary material ispulled off under tension to be applied to the workpiece; supply meanscarrying a supply of the filamentary material and being rotatable inresponse to withdrawal of such material which is being furnished to saidoutput means; braking means displaceable between a first and a secondoperative mode in which it respectively permits and prevents rotation ofsaid supply means and withdrawal of the filamentary material from thesame; loop-forming means permanently tending to move from an inoperativeposition to an operative position in which it forms a storage loop froma length of said filamentary material intermediate said output means andsaid supply means, said loopforming means being responsive with movementto said operative position to a displacement of said braking means intosaid first mode and causing displacement of said braking means back intosaid second moDe as a consequence of the formation of the loop, wherebysaid output means can withdraw filamentary material only from said loopuntil said length of filamentary material is used up and saidloop-forming means is moved to said inoperative position; and releasemeans for displacing said braking means into said first mode inautomatic response to movement of said loop-forming means toward saidinoperative position.
 2. A combination as defined in claim 1, whereinsaid supply means comprises a pin and at least one filamentary-materialcarrying spool mounted for rotation about said pin and having a freeaxial end; said braking means comprising an arm extending across saidfree axial end substantially normal to said pin and having one endportion mounted for pivotal movement about a pivot axis extending normalto both said pin and the elongation of said arm, and a friction membercarried by said arm and engageable with said free axial end of saidspool.
 3. A combination as defined in claim 2, said arm having anotherend portion spaced from said one end portion and carrying a first rollermounted turnably thereon and about which said filamentary material istrained; further comprising a second roller mounted adjacent saidloop-forming means and engaging said filamentary material intermediatesaid supply means and said first roller.
 4. A combination as defined inclaim 3, said first and second roller being rotatable aboutsubstantially parallel first and second axes; and wherein saidloop-forming means comprises a third roller rotatable about a third axessubstantially parallel to said first and second axes, and a pivot armhaving one portion on which said third roller is mounted, and anotherportion which is pivoted for displacement about a fourth axisparalleling said third axis, said filamentary material being alsotrained about said third roller downstream of said second roller withreference to the direction of movement of said filamentary materialtowards said output means, so that when said loop is formed by movementof said third roller with said pivot arm in said direction, said loopincludes two filament portions which extend between said first andsecond rollers and between said second and third rollers, respectively,and which include with one another an angle which varies in dependenceupon the extent to which said pivot arm is displaced about said pivotaxis.
 5. A combination as defined in claim 4; and further comprising arotary support having an axis of rotation, said means all being mountedon said support for rotation with the same.
 6. A combination as definedin claim 5, wherein said arm extends substantially parallel to a planein which said support rotates, and said pin extends substantiallyparallel to said axis of rotation of said support.
 7. A combination asdefined in claim 6, wherein said arm extends substantially radially ofsaid rotary support.
 8. A combination as defined in claim 5, whereinsaid two filament portions are located in a common plane which extendssubstantially radially of said rotary support.
 9. A combination asdefined in claim 4, wherein said angle is open in direction towards saidrotary support.